https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70662
Bug ID: 70662 Summary: vpbroadcastq assemble failure with -masm=intel -mavx512vbmi Product: gcc Version: 6.0 Status: UNCONFIRMED Keywords: assemble-failure Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: zsojka at seznam dot cz Target Milestone: --- Target: x86_64-pc-linux-gnu Created attachment 38267 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38267&action=edit reduced testcase Compiler output: $ gcc -Og -fschedule-insns -fno-tree-fre -mavx512vbmi --param=max-sched-ready-insns=1 -masm=intel testcase.c /tmp/cc4IEVUE.s: Assembler messages: /tmp/cc4IEVUE.s:383: Error: operand size mismatch for `vpbroadcastq' The failing instruction is: vpbroadcastq zmm17{k1}, XMMWORD PTR [rsp+4536] s/XMMWORD/QWORD/ fixes the assembly. The second operand is a QWORD, but if a register is referenced, it is an XMM register (only 64 bits are used).